Here was the next stage:
I have now darkened all the robes, and the chains, and I have sketched in all the necessary linear detail from the drawing layer onto a paint layer. But I see that my goal of a high contrast illustration is getting away from me again, so...
...here I opened a brand new layer in the Photoshop file and sketched in the values and colors I wanted to arrive at, but in a careless and slapdash fashion, all very rough; now I find myself much closer to where I want to be. Note that none of this layer will actually appear in the final, but the layer will guide me to the values and saturation I want.
However, the above screen shot does include some detail work on figures two and three in line, the young woman and the leering man.
Next: The Problem of the Leering Man